Field of the Invention
The present invention relates to a mold apparatus for casting a cylinder block, for cast-molding a cylinder block having a cast-in cylinder liner by installing the cylinder liner inside a cavity and pouring a melt into the cavity.
Background Information
A configuration of this kind of mold apparatus for casting a cylinder block hitherto has been proposed (see, for example, Japanese Patent No. 4326395), in which a movable mold is formed by insertion-coupling a bore pin for holding a cast-in sleeve, on an inner perimeter of a water jacket-forming insert, the mold is closed in a state in which the cast-in sleeve is fitted on the bore pin, so that one end face in a longitudinal direction of the cast-in sleeve contacts with a step part on the stepped bore pin, and the mold is then filled with an aluminum melt, whereby an overcasting-type cylinder block, in which an end face on a deck-surface side on the cast-in sleeve is enclosed by the aluminum melt, is cast-molded.
In this apparatus, a surface-roughened part is formed on the insertion-coupling surface between the bore pin and the water jacket, and gas accumulating inside an elongated blocked-off cavity formed by the end face on the deck-surface side of the cast-in sleeve, a movable core, and the step part of the bore pin is discharged from the surface-roughened part. That is, the surface-roughened part is used as a gas discharge passage.